Operating device for perpetual calendar

ABSTRACT

An operating mechanism for a perpetual calendar has coaxial date and month wheels of equal diameter whose circumferential faces have respective equal portions corresponding to the 31 days of a month and to the twelve months of the year. The date wheel face has a radial notch in the section corresponding to the 30th day, and the month wheel face has notches in the sections corresponding to the months having fewer than 31 days. The wheels are connected by an intermediate gear which turns the month wheel through one circumferential section when the date wheel is turned through 31 sections by a pawl-and-ratchet drive. The effective stroke of the pawl is doubled by a control mechanism responding to axial alignment of the notch in the date wheel with one of the notches in the month wheel.

United States Patent 1191 Sato Oct. 7, 1975 OPERATING DEVICE FOR PERPETUAL CALENDAR Primary ExaminerRobert W. Michell Assistant ExaminerJohn H. Wolff [75] Inventor. Rel]! Sato, Yokohama, Japan Attorney Agent or Firm Hans Berman [73] Assignee: Amano Corporation, Yokohama,

Japan 57 ABSTRACT [22] Filed: Dec. 28, 1973 An operating mechanism for a perpetual calendar has [21] A I No I 429 383 coaxial date and month wheels of equal diameter pp whose circumferential faces have respective equal portions corresponding to the 31 days of a month and [52] US. Cl. 40/107; 58/4; 235/135 to the twelve months of the year. The date wheel face [51] Int. Cl. G09D 3/00 has a radial notch in the section corresponding to the [58] Field of Search 40/ 107; 30th day, and the month wheel face has notches in the 58/4-6, 58; 346/86; 235/125 sections corresponding to the months having fewer than 31 days. The wheels are connected by an inter- [56] References Cited mediate gear which turns the month wheel through UNITED STATES PATENTS one circumferential section when the date wheel is turned through 31 sections by a pawl-and-ratchet 1,795,085 3 1931 D 5 l X 2,389,345 1945 i a Z1 3 dr1ve. The effective stroke of the pawl 1s doubled by a 2,566,125 8/1951 Fehr t I I 58/4 X control mechanism responding to axial alignment of 3,681,913 8/1972 Solari 40/107 x the notch in the date Wheel with one Of the notches in FOREIGN PATENTS OR APPLICATIONS Germany 235/135 the month wheel.

4 Claims, 6 Drawing Figures US Patent Oct. 7,1975 Sheet 1 ofi 3,909,966

US. Patent Oct. 7,1975 Sheet 2 of2 3,909,966

OPERATING DEVICE FOR PERPETUAL CALENDAR BACKGROUND OF THE INVENTION This invention relates to perpetual calendars, and particularly to an operating mechanism for a perpetual calendar.

A perpetual calendar automatically indicating the months of the year and the date of the month must be equipped with an operating mechanism capable of discriminating between the months having 31 days and the shorter months so that the calendar switches directly to the first day of the next month from the properly selected last day of the preceding month. The known devices for accomplishing this mode of operation are relatively complex and correspondingly costly and subject to malfunctionings.

A primary object of this invention is the provision of an operating mechanism of the type described which is of small size, has a minimum of parts, and can be manufactured simply and at low cost, yet accurately switches the date indication in accordance with the length of the month.

SUMMARY OF THE INVENTION With this object and others in view, the invention provides an operating mechanism for a perpetual calendar which includes a date wheel having a circumferential face of which 31 equal sections are associated with 31 days of a month respectively. Thirty sections have a common radius, and the section associated with the 30th day of the month has a radius different from that common radius. A month wheel coaxial with the date wheel has a circumferential face in which 12 equal sections are associated with the 12 months of the year respectively. The sections associated with the months having 31 days have the afore-mentioned common radius, and the respective radii of the sections associated with the months having 30 days are different from the common radius. A gear transmission connects the two wheels in such a manner that the month wheel is advanced angularly by one section of its circumferential face in response to angular advance of the date wheel by the afore-mentioned 31 sections. An actuating device cyclically advances the date wheel in angular steps. Acontrol device senses the respective radii of axially aligned sections of the two wheel faces, and is operatively connected to the actuating device for causing advancing of the date wheel in a step corresponding to one section of the date wheel when at least one of the sensed aligned sections is of the aforementioned common radius while causing the date wheel to advance in a step corresponding to two sections of the date wheel when the sensed aligned sections are each of the respective different radii.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the calendar operating mechanism of this invention as applied to a time recorder;

FIG. 2 shows a portion of the mechanism of FIG. 1 in top plane view; and

FIGS. 3 to 6 show elements of the mechanism in side elevation and partly in section.

DETAILED DESCRIPTION FIGS. I and 2 show an actuating shaft 1 and a ratchet wheel 2 fixedly fastened to the shaft by means of a set screw 21; in a hub portion 2a of the wheel 2 which has 31 teeth uniformly distributed over its circumference. The ratchet wheel 2 may be advanced one tooth per day as will presently be explained. A wheel 3 is integral with the hub portion 2a. Two teeth 4 circumferentially juxtaposed on the periphery of the wheel 3 engage an intermediate pinion 5 once during each revolution of the wheel 3.

A date wheel 8 is fixedly fastened to the shaft 1, and thereby to the ratchet wheel 2, by a set screw 8c in a hub portion 8b of the wheel 8. Its circumference is divided into 31 equal sections 8', and the section corresponding to the 30th day is provided with a radial notch 80, better seen in FIG. 4. The wheels 7, 8 are of equal overall radius and axially juxtaposed so that a sensing tooth 9a of a control arm 9 rests simultaneously on the circumferential faces of both wheels 7, 8. The arm 9 is hingedly mounted on non-illustrated structure for pivotal movement about an axis remote from the shaft 1. When notches 7a, 8a of the two wheels are axially aligned on the 30th day of each month having less than 31 days, the tooth 9a drops into the aligned notches under the pressure of a pawl spring 15.

The drive mechanism which normally advances the ratchet wheel 2 by one tooth per day includes a supporting frame 10 which is mounted on the shaft for pivoting movement by a link 11 connected to a nonillustrated solenoid. The solenoid is energized briefly once a day by a non-illustrated electric clock work. A shaft 14' on the frame 10 is spacedly parallel to the shaft 1 and carries a pawl 12 and a pawl-shaped engaging arm 13 which are fixedly connected by a tube 14 partly enveloping the shaft 14. The pawl 12 drivingly engages the ratchet wheel 2, and the arm 13 rides on the top face of the control arm 9 which is provided with a convex cam portion 9b, as is best seen in FIGS. 5 and 6. The arm 9 is interposed between the wheels 7, 8 and the engaging arm 13, the tooth 9a and cam portion 9b being spaced from the pivot axis of the arm 9.

When the tooth 9a travels over the lands of the month wheel 7 and/or the smooth circular circumference of the date wheel 8, the pawl 12 and the arm 13 are raised by the cam portion 9b of the control arm 9 during the daily pivoting movement of the frame 10 so that the pawl 12 can advance the ratchet wheel 2 by one tooth only, as is shown in FIG. 5.

When notches 7a, 8a in the wheels 7, 8 are axially aligned under the tooth 9a, the cam 9b is lowered sufficiently toward the common axis of the wheels 7, 8 together with the arm 13 and the pawl 12 by the pawl spring 15 that the pawl 12 advances the ratchet wheel 2 by a stroke of two steps during the pivoting movement of the frame 10. Therefore, the 31st day is skipped in each month having only 30 days, and the calendar mechanism moves from the 30th day of each month having fewer than 31 days to the first day of the next month.

FIG. 1 shows the cooperation of the afore-described calendar mechanism with a time recorder in which time is recorded in a knownmanner on a card 16 by a printing device, not shown, mounted on a fixed level while the card is set vertically to align the printing device with date lines arranged on the card 16 in two columns respectively for the first 16 days of the month and for the remainder of the month to a 31st day.

The vertical position of a card inserted in the time recorder is determined by an upright rack 17 cooperating with a gear 18 whose rim of ratchet teeth is interrupted by two diametrically opposite gaps 18a, 18b. The gear 18 is fixedly fastened on the shaft 1 and lifts the rack in normal steps of one tooth spacing during the first 16 days of each month until the rack 17 drops when facing the gap 18a on the 17th day. An abutment 17a on the rack 17 limits the drop of the rack to a position in which the non-illustrated 17th day line is aligned with the printing mechanism. The rack is again dropped on the 31st day of a long month, and on the 30th day of a short month, when it faces the gap 18b in the toothed rim of the gear 18, having been lifted in a step of two tooth spacings by the shaft 1 in the shorter month.

Obviously, the operating mechanism for a perpetual calendar provided by the invention is not limited to a time recorder, but may be used with other perpetual calendars, such as those of the needle type or of the flap type, without basic changes.

Digital indicia for days and months are shown in the drawing for the convenience of the description only.

The calendar operating mechanism of the invention has a very small number of parts which are made and assembled easily. The mechanism, therefore, is inexpensive, compact, and free from operating trouble.

The device of the invention treats February like a month having 30 days. It is necessary, therefore, manually to reciprocate the frame at the end of February twice in an ordinary year and once in a leap year.

What is claimed is:

1. An operating mechanism for a perpetual calendar comprising:

a. a date wheel (8) having a circumferential face,

1. 31 equal sections of said face being associated with 31 days of a month respectively,

2. 30 of said sections (8') being of a common radius, and the section (8a) associated with the 31st day of the month being of a smaller radius;

b. a month wheel (7) coaxial with said date wheel and having a circumferential face,

1. twelve equal sections of said face being associated with the twelve months of the year respectively,

2. the sections (7) of the face of said month wheel associated with the months having 31 days being of said common radius, and the sections (7a) associated with the months having 30 days being of a smaller radius,

3. said sections of smaller radius constituting radial notches in said faces of said date wheel and said month wheel respectively;

0. transmission means (4, 5, 6) operatively interposed between said wheels and angularly advancing said month wheel by one section of said face thereof in response to angular advance of said date wheel by said 31 sections of the latter;

d. actuating means for cyclically advancing said date wheel in angular steps, said actuating means including l. a ratchet wheel (2) connected to said date wheel for joint rotation about the common axis of said date wheel and said month wheel,

2. a support (10),

3. means (11) for pivoting said support about said common axis,

4. a driving pawl (12) movably mounted on said support and drivingly engaging said ratchet wheel during said cyclic advancing; and

e. control means for sensing the respective radii of axially aligned sections of said faces and operatively connected to said actuating means for advancing of said date wheel in a step corresponding to one section of said date wheel when at least one of said sensed aligned sections is of said common radius, and for causing advancing of said date wheel in a step corresponding to two sections of said date wheel when the sensed aligned sections are notches by varying the effective stroke of said driving pawl, said control means including 1. a control arm (9) having a sensing portion (9a) and a cam portion (9b) and movably mounted for simultaneous engagement of said sensing portion with said faces,

2. means (15) biasing said control member to move toward said common axis when said sensing portion simultaneously engages notches in said faces,

3. an engaging member (13) connected to said driving pawl for joint movement therewith relative to said support, said engaging member engaging said cam portion for moving said driving pawl of said support in response to the position of the engaged control member relative to said common axis between respective positions of different effective stroke.

2. A mechanism as set forth in claim 1, wherein said control arm is mounted for pivotal movement about an axis remote from said common axis, said cam portion and said sensing portion being spaced from the axis of pivotal movement of said control arm.

3. A mechanism as set forth in claim 2, wherein said cam portion and said sensing portion are interposed between said faces and said engaging member.

4. A mechanism as set forth in claim 1, further comprising date indicating means connected to said date wheel for indicating the angular position of said date wheel. 

1. An operating mechanism for a perpetual calendar comprising: a. a date wheel (8) having a circumferential face,
 1. 31 equal sections of said face being associated with 31 days of a month respectively,
 2. 30 of said sections (8'') being of a common radius, and the section (8a) associated with the 31st day of the month being of a smaller radius; b. a month wheel (7) coaxial with said date wheel and having a circumferential face,
 1. twelve equal sections of said face being associated with the twelve months of the year respectively,
 2. the sections (7'') of the face of said month wheel associated with the months having 31 days being of said common radius, and the sections (7a) associated with the months having 30 days being of a smaller radius,
 3. said sections of smaller radius constituting radial notches in said faces of said date wheel and said month wheel respectively; c. transmission means (4, 5, 6) operatively interposed between said wheels and angularly advancing said month wheel by one section of said face thereof in response to angular advance of said date wheel by said 31 sections of the latter; d. actuating means for cyclically advancing said date wheel in angular steps, said actuating means including
 1. a ratchet wheel (2) connected to said date wheel for joint rotation about the common axis of said date wheel and said month wheel,
 2. a support (10),
 3. means (11) for pivoting said support about said common axis,
 4. a driving pawl (12) movably mounted on said support and drivingly engaging said ratchet wheel during said cyclic advancing; and e. control means for sensing the respective radii of axially aligned sections of said faces and operatively connected to said actuating means for advancing of said date wheel in a step corresponding to one section of said date wheel when at least one of said sensed aligned sections is of said common radius, and for causing advancing of said date wheel in a step corresponding to two sections of said date wheel when the sensed aligned sections are notches by varying the effective stroke of said driving pawl, said control means including
 1. a control arm (9) having a sensing portion (9a) and a cam portion (9b) and movably mounted for simultaneous eNgagement of said sensing portion with said faces,
 2. means (15) biasing said control member to move toward said common axis when said sensing portion simultaneously engages notches in said faces,
 3. an engaging member (13) connected to said driving pawl for joint movement therewith relative to said support, said engaging member engaging said cam portion for moving said driving pawl of said support in response to the position of the engaged control member relative to said common axis between respective positions of different effective stroke.
 2. 30 of said sections (8'') being of a common radius, and the section (8a) associated with the 31st day of the month being of a smaller radius; b. a month wheel (7) coaxial with said date wheel and having a circumferential face,
 2. the sections (7'') of the face of said month wheel associated with the months having 31 days being of said common radius, and the sections (7a) associated with the months having 30 days being of a smaller radius,
 2. a support (10),
 2. means (15) biasing said control member to move toward said common axis when said sensing portion simultaneously engages notches in said faces,
 2. A mechanism as set forth in claim 1, wherein said control arm is mounted for pivotal movement about an axis remote from said common axis, said cam portion and said sensing portion being spaced from the axis of pivotal movement of said control arm.
 3. A mechanism as set forth in claim 2, wherein said cam portion and said sensing portion are interposed between said faces and said engaging member.
 3. an engaging member (13) connected to said driving pawl for joint movement therewith relative to said support, said engaging member engaging said cam portion for moving said driving pawl of said support in response to the position of the engaged control member relative to said common axis between respective positions of different effective stroke.
 3. means (11) for pivoting said support about said common axis,
 3. said sections of smaller radius constituting radial notches in said faces of said date wheel and said month wheel respectively; c. transmission means (4, 5, 6) operatively interposed between said wheels and angularly advancing said month wheel by one section of said face thereof in response to angular advance of said date wheel by said 31 sections of the latter; d. actuating means for cyclically advancing said date wheel in angular steps, said actuating means including
 4. a driving pawl (12) movably mounted on said support and drivingly engaging said ratchet wheel during said cyclic advancing; and e. control means for sensing the respective radii of axially aligned sections of said faces and operatively connected to said actuating means for advancing of said date wheel in a step corresponding to one section of said date wheel when at least one of said sensed aligned sections is of said common radius, and for causing advancing of said date wheel in a step corresponding to two sections of said date wheel when the sensed aligned sections are notches by varying the effective stroke of said driving pawl, said control means including
 4. A mechanism as set forth in claim 1, further comprising date indicating means connected to said date wheel for indicating the angular position of said date wheel. 